A private equity executive bought one of the Fifth Avenue co-ops owned by the late copper heiress Huguette Clark for $22.5 million, public records show.

Frederick Iseman — who founded CI Capital Partners — asked the co-op board to join one apartment, priced at $19 million, with part of another that was also owned by Clark for an additional $3.5 million.

The co-op board approved Iseman’s request, even though it had recently rejected a similar one Sheikh Hamad bin Jassim bin Jaber Al Thani, the Prime Minister of Qatar.

At the time, sources told the Post that the board was worried about the sheer number of people who would have access to the apartment. The Sheik has multiple wives, 15 children, and a large gun-toting security detail – as well as diplomatic status that might hinder the board’s ability to legally settle potential disputes.

Iseman’s new purchase, on the eighth floor, is known as 8W, which was asking $19 million, plus a piece of 8E, which upped the price to $22.5 million.

The remaining eighth floor unit is expected to go back on the market soon, brokers told The Post.

Built in 1915, the 12 story limestone building between 71st and 72nd St was built in the Italian Renaissance palazzo style around a central court. It received a gold medal from the American Institute of Architects in 1916.

Clark, a recluse who died at 104, owned three units in the building – in total, 42 rooms with 17,000 square feet, including 10,000 square feet facing Central Park.

At one time, all three units were rumored to be worth $100 million.

However, the fact that they were unconnected and were in poor condition –they hadn’t been updated and were in desperate need of renovation – lowered their value.

Boaz Weinstein, a finance whiz and chess master, bought one of the higher level Clark units — a four bedroom, four bath unit for $25.5 million — in June.